Generally, a motor has a stator coupled to the inner peripheral surface of a cylindrical housing and a rotor with a rotary shaft rotatably coupled to the center of the stator, so that as the rotor is rotated with the power supplied from the outside, the motor operates the rotary shaft protruded outwardly from the rotor.
Further, the motor has a disc-shaped bearing cover coupled to the top end periphery of the housing by means of coupling means like bolts, so that the bearing cover is coupled to the housing to constitute the outer shape of the motor and to support the rotation of the rotor.
At this time, the bearing cover has a bearing disposed at the inner side of the center thereof so as to reduce the friction with the contacted surface with the rotary shaft and to continuously maintain accurate coupling position with the stator, and accordingly, the formation of the bearing enables the rotor to be stably rotated.
Such motor is widely used as a drive system of electric appliances including air conditioners, and if grounding fails, a user may get shocked by leakage current. Further, high frequency noise may be generated by leakage current, thus causing peripheral devices to be malfunctioned.
If the leakage current flows through the bearing, particularly, a spark, that is, an arc is generated from the narrow space of the bearing to cause the bearing to be electrically corroded, so that grooves may be undesirably formed on the surface of the bearing, thus making the bearing easily destructed.
For the grounding of the motor, accordingly, a separate ground frame is formed on the bearing cover, and otherwise, a hole is formed on the bearing cover so as to fix a ground terminal thereto. However, these methods make the bearing cover undesirably complicated in structure, thus increasing the total size of the motor, making it hard to perform the installating and disassembling works, and increasing the work efforts necessary for the assembly of the motor.